So confused 😩

So my supposed period was late. I bled lightly, (not even enough to fill a pad,) for 3 days. This is very odd for me. Normally I bleed for 5 days, with awful cramps the first 3 days, & I go through a couple pads. I've also had some nausea, urinating more often, & gas. Tonight after my boyfriend & I had sex & he fingered me, there was no blood on his penis or fingers. A few minutes later, I was bleeding. Took hpt about a week ago, was negative. Ovulated maybe 4 weeks ago. (Sorry for long post.) what is going on??